Transit of Venus
A transit of Venus across the Sun happens when the planet Venus goes between the Sun and Earth. It is a syzygy and a partial occultation of the Sun. When a transit happens, Venus can be seen as a small black dot going across the Sun. Transits of Venus usually take several hours.
Transits of Venus are among the rarest of predictable events which happen in astronomy. They occur in a pattern that repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years.
The most recent transit of Venus happened on 5 and 6 June 2012. It was the last Venus transit this century. The one before took place on 8 June 2004. The next transits of Venus will be in December 2117 and December 2125.
The transit on 5 and 6 June 2012 was broadcast live on the Internet.[1]
During the 18th century, astronomers tried to use transits of Venus to measure the astronomical unit, the distance from the Earth to the Sun. Many countries sent expeditions to distant lands to observe the transits from places as far apart as possible for maximum parallax.
One of the most famous expeditions was the voyage of Lieutenant James Cook in the HMS Endeavour.
Transit Of Venus Media
Image of the 2012 transit taken by NASA's Solar Dynamics Observatory spacecraft
Diagram of transits of Venus and the angle between the orbital planes of Venus and Earth
"Venus Tablet of Ammisaduqa", a cuneiform clay tablet of astrological forecasts from the Neo-Assyrian period
Jeremiah Horrocks makes the first observation of the transit of Venus in 1639, as imagined by the artist W. R. Lavender in 1903
Diagram from Edmund Halley's 1716 paper to the Royal Society showing how Venus's transit could be used to calculate the distance between the Earth and the Sun
Measuring Venus transit times to determine solar parallax
Account of George III's observations of the 1769 transit.
Diagram from David Rittenhouse's observations of the 1769 transit of Venus
The "black drop effect" as recorded during the 1769 transit
Photographic sequence of 1874 passage of Venus over the face of the sun, it was the first-ever moving picture
Solar Dynamics Observatory Ultra-high Definition View of the 2012 Transit of Venus
This visualization shows the orbital paths of Venus and Earth that led to this rare alignment on 5–6 June 2012
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References
- ↑ "2012 Transit of Venus". NASA. Archived from the original on 2012-06-09. Retrieved 2012-06-09.
